Robust Three-Dimensional High-Order Solitons and Breathers in Driven Dissipative Systems: A Kerr Cavity Realization.

We present a general approach to excite robust dissipative three-dimensional and high-order solitons and breathers in passively driven nonlinear cavities. Our findings are illustrated in the paradigmatic example provided by an optical Kerr cavity with diffraction and anomalous dispersion, with the addition of an attractive three-dimensional parabolic potential. The potential breaks the translational symmetry along all directions, and impacts the system in a qualitatively unexpected manner: three-dimensional solitons, or light bullets, are the only existing and stable states for a given set of parameters. This property is extremely rare, if not unknown, in passive nonlinear systems. As a result, the excitation of the cavity with any input field leads to the deterministic formation of a target soliton or breather, with a spatiotemporal profile that unambiguously corresponds to the given cavity and pumping conditions. In addition, the tuning of the potential width along the temporal direction results in the existence of a plethora of stable asymmetric solitons. Our results may provide a solid route toward the observation of dissipative light bullets and three-dimensional breathers.

High-temperature wave thermalization spoils beam self-cleaning in nonlinear multimode GRIN fibers.

In our experiments, we reveal a so-far unnoticed power limitation of beam self-cleaning in graded-index nonlinear multimode optical fibers. As the optical pulse power is progressively increased, we observed that the initial Kerr-induced improvement of the spatial beam quality is eventually lost. Based on a holographic mode decomposition of the output field, we show that beam spoiling is associated with high-temperature wave thermalization, which depletes the fundamental mode in favor of a highly multimode power distribution.

Modal phase-locking in multimode nonlinear optical fibers.

Spatial beam self-cleaning, a manifestation of the Kerr effect in graded-index multimode fibers, involves a nonlinear transfer of power among modes, which leads to robust bell-shaped output beams. The resulting mode power distribution can be described by statistical mechanics arguments. Although the spatial coherence of the output beam was experimentally demonstrated, there is no direct study of modal phase evolutions. Based on a holographic mode decomposition method, we reveal that nonlinear spatial phase-locking occurs between the fundamental and its neighboring low-order modes, in agreement with theoretical predictions. As such, our results dispel the current belief that the spatial beam self-cleaning effect is the mere result of a wave thermalization process.

Dissipative Kerr solitons, breathers, and chimera states in coherently driven passive cavities with parabolic potential.

We analyze the stability and dynamics of dissipative Kerr solitons (DKSs) in the presence of a parabolic potential. This potential stabilizes oscillatory and chaotic regimes, favoring the generation of static DKSs. Furthermore, the potential induces the emergence of new dissipative structures, such as asymmetric breathers and chimera-like states. Based on a mode decomposition of these states, we unveil the underlying modal interactions.

Linking neuroanatomical abnormalities in autism spectrum disorder with gene expression of candidate ASD genes: A meta-analytic and network-oriented approach.

BACKGROUND: Autism spectrum disorder (ASD) is a set of developmental conditions with widespread neuroanatomical abnormalities and a strong genetic basis. Although neuroimaging studies have indicated anatomical changes in grey matter (GM) morphometry, their associations with gene expression remain elusive. METHODS: Here, we aim to understand how gene expression correlates with neuroanatomical atypicalities in ASD. To do so, we performed a coordinate-based meta-analysis to determine the common GM variation pattern in the autistic brain. From the Allen Human Brain Atlas, we selected eight genes from the SHANK, NRXN, NLGN family and MECP2, which have been implicated with ASD, particularly in regards to altered synaptic transmission and plasticity. The gene expression maps for each gene were built. We then assessed the correlation between the gene expression maps and the GM alteration maps. Lastly, we projected the obtained clusters of GM alteration-gene correlations on top of the canonical resting state networks, in order to provide a functional characterization of the structural evidence. RESULTS: We found that gene expression of most genes correlated with GM alteration (both increase and decrease) in regions located in the default mode network. Decreased GM was also correlated with gene expression of some ASD genes in areas associated with the dorsal attention and cerebellar network. Lastly, single genes were found to be significantly correlated with increased GM in areas located in the somatomotor, limbic and ganglia/thalamus networks. CONCLUSIONS: This approach allowed us to combine the well beaten path of genetic and brain imaging in a novel way, to specifically investigate the relation between gene expression and brain with structural damage, and individuate genes of potential interest for further investigation in the functional domain.

Multimode soliton collisions in graded-index optical fibers.

In this work, we unveil the unique complex dynamics of multimode soliton interactions in graded-index optical fibers through simulations and experiments. By generating two multimode solitons from the fission of an input femtosecond pulse, we examine the evolution of their Raman-induced red-shift when the input pulse energy grows larger. Remarkably, we find that the output red-shift of the trailing multimode soliton may be reduced, so that it accelerates until it collides with the leading multimode soliton. As a result of the inelastic collision, a significant energy transfer occurs between the two multimode solitons: the trailing soliton captures energy from the leading soliton, which ultimately enhances its red-shift, thus increasing temporal separation between the two multimode solitons.

Surgical contraception of free-ranging female capybaras: Description and comparison of open and minimally invasive techniques.

OBJECTIVE: To develop, describe, and evaluate 2 surgical techniques for contraception of free-ranging female capybaras. STUDY DESIGN: Prospective study. ANIMALS: Cadaveric (n = 3) and free-ranging female capybaras (n = 21). METHODS: Preliminary studies of surgical anatomy were performed on 3 capybara cadavers. Two different techniques for partial salpingectomy were evaluated in free-ranging female capybaras: bilateral minilaparotomy (LTG; n = 11) or bilateral laparoscopy (LCG; n = 10). Data concerning body weight, tubal ligation time, total surgical time, incision size, and intraoperative and postoperative complications were analyzed, as well as the clinical status and incisional healing 1 week postoperatively. RESULTS: Body weight (P = .214), ligation time of the left uterine tube (P = .901), and total surgical time (P = .473) were similar between the experimental groups. The ligation time of the right uterine tube was shorter in the LCG group (P = .0463). In the LTG, no differences were observed between the sides regarding the incision size (P = .478). No major intraoperative or postoperative complications occurred in either group. One LCG procedure had to be converted to LTG due to technical issues. All skin incisions healed without complication. CONCLUSION: Both procedures showed similar and satisfactory outcomes. CLINICAL SIGNIFICANCE: The proposed techniques may be a suitable alternative to conventional laparotomy for contraception of female capybaras, especially under field conditions.

Multimode solitons in step-index fibers.

We experimentally generate multimode solitons in step-index fibers, where nonlinearity compensates for both chromatic and modal dispersion. These solitons are subject to Raman self-frequency shift, and their energy is gradually transfered to the fundamental fiber mode. We compare multimode soliton dynamics in both step-index and graded index fibers, in excellent agreement with numerical predictions.

Comparative study between S-(+)-ketamine­midazolam and fentanyl­droperidol in black-tufted marmosets (Callithrix penicillata) / Estudo comparativo entre S-(+)cetamina-midazolam e fentanil-droperidol em saguis-de-tufo-preto (Callithrix penicillata)

Sedative and antinociceptive effects of two anesthetic protocols in black-tufted marmosets were compared in this study. Twenty-six marmosets underwent chemical immobilization for physical examination, blood sampling, tattooing, and microchipping. Animals were randomly treated with S-(+)-ketamine (10 mg/kg) and midazolam (1 mg/kg) (KM) or fentanyl (12.5 µg/kg) and droperidol (625 µg/kg) (FD) given by intramuscular injection. Heart and respiratory rates were recorded. Sedation, antinociception, muscle relaxation, posture, auditory, and visual responses were evaluated using a scoring system. Sedation in KM was achieved faster (p < 0.001) and lasted for a shorter period of time (p = 0.0009). KM was similar to FD in its cardiorespiratory effects, auditory and visual responses. Both protocols promoted adequate sedation to allow manipulation. Animals in KM assumed lateral recumbency while animals in FD maintained a quadrupedal posture during evaluation. FD produced less intense sedation and muscle relaxation but a higher degree of antinociception compared to KM and is suitable for procedures that require analgesia in black-tufted marmosets.(AU)

O presente estudo comparou os efeitos cardiorrespiratórios, sedativos e antinociceptivos de dois protocolos anestésicos em saguis-de-tufo-preto (Callithrix penicillata). Vinte e seis saguis foram submetidos à contenção química para exame físico, coleta de sangue, tatuagem de identificação e microchip. Os animais foram tratados aleatoriamente com a associação de S-(+)-cetamina (10 mg/kg) e midazolam (1 mg/kg) (KM) ou fentanil (12,5 µg/kg) e droperidol (625 µg/kg) (FD), administrados por injeção intramuscular. Foram avaliadas frequência cardíaca, frequência respiratória, sedação, antinocicepção, relaxamento muscular, postura e resposta ao estímulo auditivo e visual. A sedação em KM foi alcançada mais rapidamente (p <0,001) e teve um tempo hábil mais curto (p = 0,0009). KM foi semelhante a FD nos efeitos cardiorrespiratórios, respostas auditivas e visuais. Os dois protocolos promoveram sedação adequada para manipulação. Os animais do grupo KM permaneceram em decúbito lateral durante a avaliação, enquanto os animais em FD mantiveram postura quadrupedal. FD resultou em sedação e relaxamento muscular de menor intensidade, porém com maior escore de antinocicepção em comparação com KM, sendo adequada para procedimentos que requerem analgesia em saguis-de-tufo-preto.(AU)

Vasectomy of golden-headed lion tamarins (Leontopithecus chrysomelas) using local anesthesia after sedation with dexmedetomidine-ketamine-meperidine.

The study evaluated the combination of ketamine, dexmedetomidine, and meperidine for vasectomy in golden-headed lion tamarins. Lidocaine infiltration was required for intraoperative analgesia and atipamezole was used at the end of the procedure. The protocol promoted satisfactory sedation and analgesia with a short recovery time in tamarins.

TENORM employed as inert material for house building: a model for evaluating the radon activity enhancement.

Radon exhalation from soil and ores is among the most dangerous risks for the public health care. The impact becomes even more powerful when technological enhanced naturally occurring radioactive materials (TENORM) are used for public and private building. Here, we built a down-scaled model (a 1.0 m × 1.0 m × 0.5 m parallelepiped) of a dwelling, whose construction materials contain TENORM harvested in a site in Crotone (Italy). We observed an increase of the radon activity in the model when TENORM residues are employed, reaching a value around 120 Bq/m3, i.e. up to three times higher than the typical values of Crotone indoor environment, which ranges around 40 Bq/m3. These results have then been compared to a real use case. The correspondence found between the values of radon activity concentration in the model and in the use case suggests that estimating the radon concentration is a useful method to target TENORM presence inside buildings.

Spatiotemporal beam self-cleaning for high-resolution nonlinear fluorescence imaging with multimode fiber.

Beam self-cleaning (BSC) in graded-index (GRIN) multimode fibers (MMFs) has been recently reported by different research groups. Driven by the interplay between Kerr effect and beam self-imaging, BSC counteracts random mode coupling, and forces laser beams to recover a quasi-single mode profile at the output of GRIN fibers. Here we show that the associated self-induced spatiotemporal reshaping allows for improving the performances of nonlinear fluorescence (NF) microscopy and endoscopy using multimode optical fibers. We experimentally demonstrate that the beam brightness increase, induced by self-cleaning, enables two and three-photon imaging of biological samples with high spatial resolution. Temporal pulse shortening accompanying spatial beam clean-up enhances the output peak power, hence the efficiency of nonlinear imaging. We also show that spatiotemporal supercontinuum (SC) generation is well-suited for large-band NF imaging in visible and infrared domains. We substantiated our findings by multiphoton fluorescence imaging in both microscopy and endoscopy configurations.

Ozone Therapy in the Prevention of Dental Plaque Formation in Dogs.

This study aims to assess ozonized mineral oil ointment application as an antiplaque therapy for dogs. Domestic healthy dogs received dental scaling and polishing under general anesthesia. Under standard feeding and homecare during 7 days, 20 dogs were randomly placed into 2 different groups for dental treatment. The control group (CG) was given a single placebo application and the ozone group (O3G) received daily ozonized ointment application. The average age (CG = 4.4; O3G = 5.7 years old), body weight (CG = 15.7; O3G = 15.3 kg) and the gingivitis index obtained on the first day (D0) allowed initial homogeneity between the groups. The dental plaque index, including clinical and computerized analysis on the seventh day, was obtained from the buccal aspect of specific dental locations. Both analyses revealed significant statistical association between daily application of ozone and antiplaque effect. There was no evidence of toxicity during the study. These results suggest that ozone therapy may be an efficient adjuvant to conventional periodontal treatment in decreasing initial dental plaque formation.

BACON: A tool for reverse inference in brain activation and alteration.

Over the past decades, powerful MRI-based methods have been developed, which yield both voxel-based maps of the brain activity and anatomical variation related to different conditions. With regard to functional or structural MRI data, forward inferences try to determine which areas are involved given a mental function or a brain disorder. A major drawback of forward inference is its lack of specificity, as it suggests the involvement of brain areas that are not specific for the process/condition under investigation. Therefore, a different approach is needed to determine to what extent a given pattern of cerebral activation or alteration is specifically associated with a mental function or brain pathology. In this study, we present a new tool called BACON (Bayes fACtor mOdeliNg) for performing reverse inference both with functional and structural neuroimaging data. BACON implements the Bayes' factor and uses the activation likelihood estimation derived-maps to obtain posterior probability distributions on the evidence of specificity with regard to a particular mental function or brain pathology.

Nonlinear beam self-imaging and self-focusing dynamics in a GRIN multimode optical fiber: theory and experiments.

Beam self-imaging in nonlinear graded-index multimode optical fibers is of interest for many applications, such as implementing a fast saturable absorber mechanism in fiber lasers via multimode interference. We obtain a new exact solution for the nonlinear evolution of first and second order moments of a laser beam of arbitrary transverse shape carried by a graded-index multimode fiber. We have experimentally directly visualized the longitudinal evolution of beam self-imaging by means of femtosecond laser pulse propagation in both the anomalous and the normal dispersion regime of a standard telecom graded-index multimode optical fiber. Light scattering out of the fiber core via visible photo-luminescence emission permits us to directly measure the self-imaging period and the beam dynamics. Spatial shift and splitting of the self-imaging process under the action of self-focusing are also revealed.

High-energy soliton fission dynamics in multimode GRIN fiber.

The process of high-energy soliton fission is experimentally and numerically investigated in a graded-index multimode fiber. Fission dynamics is analyzed by comparing experimental observations and simulations. A novel nonlinear propagation regime is observed, where solitons produced by the fission have a nearly constant Raman wavelength shift and same pulse width over a wide range of soliton energies.

Optical Phase Transition in Semiconductor Quantum Metamaterials.

Unexpected light propagation effects, such as negative refraction, have been reported in artificial media. Leveraging on the intersubband resonances in heterostructured semiconductors, we show that all possible optical regimes, ranging from classical dieletric and metal to hyperbolic metamaterial types 1 and 2, can be achieved. As a demonstration, we prove that the negative refraction effect can occur at a designed frequency by controlling the electronic quantum confinement.

Early reversal of ketamine/dexmedetomidine chemical immobilization by atipamezole in golden-headed lion tamarins (Leontopithecus chrysomelas).

BACKGROUND: A smooth and rapid recovery from anesthesia allowing safe release is desirable, especially for wild species. This study describes the clinical effects of the combination of dexmedetomidine and ketamine and the partial reversal with atipamezole in golden-headed lion tamarins. METHODS: Dexmedetomidine 10 µg kg-1 and ketamine 15 mg kg-1 were administered to 45 golden-headed lion tamarins undergoing vasectomy. Following surgery, animals were assigned to three groups: control (SAL; 0.9% NaCl), atipamezole 20 µg kg-1 (ATI20), and atipamezole 40 µg kg-1 (ATI40). RESULTS AND CONCLUSIONS: All animals presented great scores of sedation and muscle relaxation during the procedure. Recovery in the control group was smooth and uneventful. Salivation, muscle tremors, and head movements were observed in ATI 20 and ATI40. The administration of atipamezole did not change total recovery times (ATI20 69 ± 23 minutes; ATI40 72 ± 45 minutes; SAL 57 ± 23 minutes).

Combination therapies and intra-tumoral competition: Insights from mathematical modeling.

Drug resistance is one of the major obstacles to a successful treatment of cancer and, in turn, has been recognized to be linked to intratumoral heterogeneity, which increases the probability of the emergence of cancer clones refractory to treatment. Combination therapies have been introduced to overcome resistance, but the design of successful combined protocols is still an open problem. In order to provide some indications on the effectiveness of medical treatments, a mathematical model is proposed, comprising two cancer populations competing for resources and with different susceptibilities to the action of immune system cells and therapies: the focus is on the effects of chemotherapy and immunotherapy, used singularly or in combination. First, numerical predictions of the model have been tested with experimental data from the literature and next therapeutic protocols with different doses and temporal order have been simulated. Finally the role of competitive interactions has been also investigated, to provide some insights on the role of competitive interactions among cancer clones in determining treatment outcomes.

Evaluation of three chemical immobilization protocols in golden-headed lion tamarins (Leontopithecus chrysomelas) undergoing vasectomy surgery.

BACKGROUND: The golden-headed lion tamarin (Leontopithecus chrysomelas), originally endemic to Bahia, was introduced in Rio de Janeiro. The species is currently found in remaining forests within the region of original occupation of the golden lion tamarin (Leontopithecus rosalia), which may compromise the survival of the golden lion tamarin. Groups of golden-headed lion tamarins were captured and translocated to Bahia. However, the area chosen reached its limit and males underwent to vasectomy procedures. METHODS: Animals were separated into 3 groups: S-ketamine and midazolam, S-ketamine and dexmedetomidine, and racemic ketamine and dexmedetomidine. RESULTS AND CONCLUSIONS: Heart rate, sedation and muscle relaxation degrees, antinociception, and lidocaine consumption presented significant difference between midazolam and dexmedetomidine groups. Bradycardia was present on dexmedetomidine groups, with values remaining within the normal range. Dexmedetomidine groups present the best outcomes for muscle relaxation, sedation, and antinociception and were safe for vasectomy surgery in golden-headed lion tamarins.